The present invention relates to an apparatus for the customization of a footwear, i.e. for the adaptation of said footwear to the specific morphology of a particular user. More specifically, the present invention relates to an apparatus for the customization of a footwear, in particular a sports footwear, which comprises an element made of a thermoplastic material. The present invention also relates to a method for the customization of a footwear, more particularly of a sports footwear which comprises an element made of a thermoplastic material, which method uses the above-mentioned apparatus.
According to prior art, footwear are manufactured in a variety of sizes, which differ in length and width. However, for each of said sizes footwear have a standardized length and width, while not all users wearing footwear of the same size have feet having the same morphology. As a consequence, a footwear, although being of the correct size, often does not fit to the specific morphology of the user's foot. This drawback is particularly relevant in the field of sports footwear, since the user's feet—during sports practice—are subject to considerable stresses.
Moreover, in the sports footwear field, compliance of the footwear to the specific morphology of the individual user significantly affects not only the comfort of the user, but also his/her performances. The above drawback is particularly limiting in the case when the sports footwear comprises a substantially rigid element.
By way of example, ski boots can be considered, which generally comprise a substantially soft inner element or inner liner and a substantially rigid outer element or outer shell. In the case of ski boots, compliance of the footwear to the morphology of the individual user's foot not only greatly increases the comfort of the user, but it also improves the maneuverability of the ski, since even minimal movements of the user's foot are effectively transmitted to the ski boot and from the ski boot to the ski.
Similar improvements both to the comfort of the user and to his/her performances can be obtained in the case of other similar sports footwear comprising a substantially rigid outer shell, such as for example roller skates or ice skates.
It is evident that the manufacturing of individual, tailor-made sports footwear, even if on the one hand would allow an effective customization of footwear themselves, on the other hand would result in high production costs and, consequently, very high, non-competitive market prices. Therefore, in the past methods and apparatuses have been developed for the customization of sports footwear starting from standard, non-customized footwear, which can therefore be manufactured on a large scale.
Still with reference to the (non-limiting) example of ski boots, known methods and apparatuses can be classified into three categories:                methods and apparatuses which provide for modifying the shape and size of the inner liner for adapting it to the morphology of the user's foot;        methods and apparatuses which provide for the introduction of an insert having variable shape and size between the user's foot and the inner liner or between the inner liner and the outer shell; and        methods and apparatus which provide for modifying the shape and size of the outer shell for adapting it to the morphology of the user's foot.        
With reference to the last category, the methods and apparatuses of known type provide for making the outer shell of the ski boot by using a thermoplastic material, so that its shape and its size can be modified if it is heated to a temperature higher than a given threshold value, and, once the outer shell has been heated, for applying to said outer shell a pressure from the outside, so that it is pressed against the user's foot. In this respect, U.S. Pat. No. 3,613,271 can be cited.
Said methods and apparatuses of the known type, however, have a number of drawbacks. First of all, generic heating means are used for bringing the temperature of the thermoplastic material above this threshold, which heating means are not specific for the application in question and may sometimes even prove to be inadequate. Furthermore, said heating means are separated and independent from the apparatus used for modifying the shape and size of the shell made of thermoplastic material. As a consequence the quality of the heating of the thermoplastic material strongly depends on the skill and experience of each operator, and proper and uniform heating of said thermoplastic material cannot be guaranteed.
Secondly, the methods and the apparatuses mentioned above may be effective in those cases in which the user's foot is, at least locally, smaller than the ski boot shell. In these cases, the compression exerted on the shell causes the shell itself to adapt itself to the morphology of the user's foot, thereby eliminating the gaps between the user's foot and the ski boot, which gaps could lead to poor comfort and worse sports performances.
However, the known methods and systems cannot be applied in those cases in which the user's foot is, at least locally, larger than the ski boot shell. This is the case, for example, of users having very protruding malleoli or having a very large sole of the foot, in particular at the metatarsal. It is evident that such a shape of the foot may result in an annoying, if not painful, pressure against the inner wall of the ski boot, which significantly reduces the user's comfort, especially during sports practice. In these cases the methods and systems of known type, which provide for pressing the shell of the boot against the foot of the user, can only worsen the situation.